What is Rigidity ?
‘Hypertonia or Muscle Tone Disorder’ is the best way to define the medical condition, also called Rigidity. It involves resistance to passive movement in the body, irrespective of posture and velocity. This disorder is also one of the significant signs and symptoms of ‘Parkinson’s Disease’. Besides, you can observe Rigidity clearly in extrapyramidal disorders. It occurs when the excessive supraspinal drive acts upon alpha motor neurons. However, spinal reflex mechanisms tend to be normal when an episode of Rigidity happens.
What is The Mechanism of Action of Rigidity ?
Typically, Rigidity occurs when an excessive supraspinal drive affects alpha motor neurons. It thereby triggers a disruption of normal reciprocal inhibition. In addition, it leads to an imbalance of inhibition and excitation at the basal ganglia and motor cortex. Finally, resulting in rigidity symptoms along with abnormalities in the posture and associated movement.
Types of Rigidity:
There are generally two types of Rigidity. They are given below:
- Cogwheel: Usually, you see this type which involves ratchet-like jerkiness in the upper extremity movements.
- Lead Pipe Rigidity: It is a rigidity form which mainly you can see in the range of motion.
Causative or Contributing Factors of Rigidity:
Like many other medical conditions, Rigidity too is triggered due to several factors. They include the following:
- Increased stretch reflexes
- Lowering of dopamine level
- The inability of an individual to relax and eliminate muscle activity
- Increase in stiffness
- Not normal activation of both agonist-antagonist muscle group
What are The Signs and Symptoms of Rigidity?
When an episode of Rigidity occurs, the following are some of its signs and symptoms you will observe the following:
- Very stiff muscles
- Cramps and pain in the muscles
- Reduction in arm swing and while walking
- Posture, which is stooped
- Unable to turn while walking
- Restricted in facial expression
Treatment and Diagnosis of Rigidity:
There are essentially two types of diagnostic tests/examinations that you can use to treat Rigidity. They include the following:
It is a form of therapy in which you use medicines. These include levodopa (L-Dopa) to treat symptoms of Rigidity and bradykinesia (slowness of movement).
Typically, this is a type of movement therapy during which various techniques of ‘Relaxation’ are used. These include yoga, rotation of the extremities, trunk, and gentle slow rocking. In the long run, this therapy proves to be very effective in reducing Rigidity.